Risk stratification in transposition of the great arteries

This thesis focused on multiple markers to predict clinical complications in adults with transposition of the great arteries after an atrial switch operation. These adults are at high risk of late complications including heart failure, arrhythmias, and premature mortality. In this thesis, we presented the first risk model that provides estimates of absolute risk of these major clinical events. Second, we showed that the use of novel markers, such as myocardial deformation and common genetic variants, can improve risk stratification over the use of basic clinical risk factors alone. Third, studies into the use of medication in adults with congenital heart disease showed that many patients use a multitude of cardiovascular drugs, even though the evidence that supports the use of these drugs is low. Lastly, studies into the genetic architecture of transposition of the great arteries and its late clinical complications provide insights in the molecular and pathophysiological mechanisms that are potentially involved in the occurrence of the congenital defect and its clinical course

Clinical course long after atrial switch: a novel risk score for major clinical events

BackgroundPatients with transposition of the great arteries corrected by an atrial switch operation experience major clinical events during adulthood, mainly heart failure (HF) and arrhythmias, but data on the emerging risks remain scarce. We assessed the risk for events during the clinical course in adulthood, and provided a novel risk score for event-free survival.Methods and ResultsThis multicenter study observed 167 patients with transposition of the great arteries corrected by an atrial switch operation (61% Mustard procedure; age, 28 [interquartile range, 24-36] years) for 13 (interquartile range, 9-16) years, during which 16 (10%) patients died, 33 (20%) had HF events, defined as HF hospitalizations, heart transplantation, ventricular assist device implantation, or HF-related death, and 15 (9%) had symptomatic ventricular arrhythmias. Five-year risk of mortality, first HF event, and first ventricular arrhythmia increased from 1% each at age 25 years, to 6% (95% CI, 4%-9%), 23% (95% CI, 17%-28%), and 5% (95% CI, 2%-8%), respectively, at age 50 years. Predictors for event-free survival were examined to construct a prediction model using bootstrapping techniques. A prediction model combining age >30 years, prior ventricular arrhythmia, age >1 year at repair, moderate or greater right ventricular dysfunction, severe tricuspid regurgitation, and mild or greater left ventricular dysfunction discriminated well between patients at low (20%) 5-year risk (optimism-corrected C-statistic, 0.86 [95% CI, 0.82-0.90]). Observed 5- and 10-year event-free survival rates in low-risk patients were 100% and 97%, respectively, compared with only 31% and 8%, respectively, in high-risk patients.ConclusionsThe clinical course of patients undergoing atrial switch increasingly consists of major clinical events, especially HF. A novel risk score stratifying patients as low, intermediate, and high risk for event-free survival provides information on absolute individual risks, which may support decisions for pharmacological and interventional management.Cardiolog

Myocardial Deformation in the Systemic Right Ventricle: Strain Imaging Improves Prediction of the Failing Heart

Background: Predicting heart failure events in patients with a sys-temic right ventricle (sRV) due to transposition of the great arteries (TGA) is important for timely intensification of follow-up. This study assessed the value of strain compared with currently used parameters as predictor for heart failureefree survival in patients with sRV.Methods: In participants of a multicentre trial, speckle-tracking echocardiography (STE) was performed to assess global longitudinal strain (GLS), mechanical dispersion (MD), and postsystolic shortening (PSS). Cox regression was used to determine the association of STE parameters with the combined end point of progression of heart failure and death, compared with cardiovascular magnetic resonance (CMR) and computed tomography (CT) derived parameters.Results: Echocardiograms of 60 patients were analyzed (mean age 34 +/- 11 years, 65% male, 35% congenitally corrected TGA). Mean GLS was -13.5 +/- 2.9%, median MD was 49 (interquartile range [IQR] 30-76) ms, and 14 patients (23%) had PSS. During a median 8 (IQR 7-9) years, 15 patients (25%) met the end point. GLS, MD, and PSS were all associated with heart failure -free survival in univariable analysis. After correction for age, only GLS (optimal cutoff 0.001), and HR 4.34, 95% CI 1.48-12.74 (P = 0.007), respectively). Combining GLS and ejection fraction improved prediction, with patients with both GLS -10.5% and sRV ejection fraction < 30% at highest risk (HR 19.69, 95% CI 4.90-79.13; P < 0.001).Conclusions: The predictive value of GLS was similar to that of CMR/ CT-derived ejection fraction. The combination of GLS and ejection fraction identified patients at highest risk of heart failure and death. Easily available STE parameters can be used to guide follow-up in-tensity and can be integrated into future risk prediction scores.Cardiolog

Medication in adults after atrial switch for transposition of the great arteries: clinical practice and recommendations

Aims Heart failure is the main threat to long-term health in adults with transposition of the great arteries (TGA) corrected by an atrial switch operation (AtrSO). Current guidelines refrain from recommending heart failure medication in TGA-AtrSO, as there is insufficient data to support the hypothesis that it is beneficial. Medication is therefore prescribed based on personal judgements. We aimed to evaluate medication use in TGA-AtrSO patients and examine the association of use of renin-angiotensin-aldosterone system (RAAS) inhibitors and beta-blockers with long-term survival.Methods and results We identified 150 TGA-AtrSO patients [median age 30 years (interquartile range 25-35), 63% male] included in the CONCOR registry from five tertiary medical centres with subsequent linkage to the Dutch Dispensed Drug Register for the years 2006-2014. Use of RAAS inhibitors, beta-blockers, and diuretics increased with age, from, respectively, 21% [95% confidence interval (CI) 14-40], 12% (95% CI 7-21), and 3% (95% CI 2-7) at age 25, to 49% (95% CI 38-60), 51% (95% CI 38-63), and 41% (95% CI 29-54) at age 45. Time-varying Cox marginal structural models that adjusted for confounding medication showed a lower mortality risk with use of RAAS inhibitors and b-blockers in symptomatic patients [hazard ratio (HR) = 0.13 (95% CI 0.03-0.73); P = 0.020 and HR = 0.12 (95% CI 0.02-0.17); P = 0.019, respectively]. However, in the overall cohort, no benefit of RAAS inhibitors and b-blockers was seen [HR = 0.93 (95% CI 0.24-3.63); P = 0.92 and HR = 0.98 (0.23-4.17); P = 0.98, respectively].Conclusion The use of heart failure medication is high in TGA-AtrSO patients, although evidence of its benefit is limited. This study showed lower risk of mortality with use of RAAS inhibitors and beta-blockers in symptomatic patients only. These findings can direct future guidelines, supporting use of RAAS inhibitors and b-blockers in symptomatic, but not asymptomatic patients.Cardiolog

Common genetic variants improve risk stratification after the atrial switch operation for transposition of the great arteries.

BACKGROUND: Clinical factors are used to estimate late complication risk in adults after atrial switch operation (AtrSO) for transposition of the great arteries (TGA), but heterogeneity in clinical course remains. We studied whether common genetic variants are associated with outcome and add value to a clinical risk score in TGA-AtrSO patients. METHODS AND RESULTS: This multicenter study followed 133 TGA-AtrSO patients (aged 28 [IQR 24-35] years) for 13 (IQR 9-16) years and examined the association of genome-wide single-nucleotide polymorphisms (SNPs) with a composite endpoint of symptomatic ventricular arrhythmia, heart failure hospitalization, ventricular assist device implantation, heart transplantation, or mortality. Thirty-two patients (24%) reached the endpoint. The genome-wide association study yielded one genome-wide significant (p 20%) risk. Stratified by the combined score, observed 5-year event-free survival was 100%, 79% and 31% for low, intermediate, and high-risk patients, respectively. CONCLUSIONS: Common genetic variants may explain some variation in the clinical course in TGA-AtrSO and improve risk stratification over clinical factors alone, especially in patients at intermediate clinical risk. These findings support the hypothesis that including genetic variants in risk assessment may be beneficial

Medication in adults after atrial switch for transposition of the great arteries: clinical practice and recommendations

Aims Heart failure is the main threat to long-term health in adults with transposition of the great arteries (TGA) corrected by an atrial switch operation (AtrSO). Current guidelines refrain from recommending heart failure medication in TGA-AtrSO, as there is insufficient data to support the hypothesis that it is beneficial. Medication is therefore prescribed based on personal judgements. We aimed to evaluate medication use in TGA-AtrSO patients and examine the association of use of renin-angiotensin-aldosterone system (RAAS) inhibitors and beta-blockers with long-term survival.Methods and results We identified 150 TGA-AtrSO patients [median age 30 years (interquartile range 25-35), 63% male] included in the CONCOR registry from five tertiary medical centres with subsequent linkage to the Dutch Dispensed Drug Register for the years 2006-2014. Use of RAAS inhibitors, beta-blockers, and diuretics increased with age, from, respectively, 21% [95% confidence interval (CI) 14-40], 12% (95% CI 7-21), and 3% (95% CI 2-7) at age 25, to 49% (95% CI 38-60), 51% (95% CI 38-63), and 41% (95% CI 29-54) at age 45. Time-varying Cox marginal structural models that adjusted for confounding medication showed a lower mortality risk with use of RAAS inhibitors and b-blockers in symptomatic patients [hazard ratio (HR) = 0.13 (95% CI 0.03-0.73); P = 0.020 and HR = 0.12 (95% CI 0.02-0.17); P = 0.019, respectively]. However, in the overall cohort, no benefit of RAAS inhibitors and b-blockers was seen [HR = 0.93 (95% CI 0.24-3.63); P = 0.92 and HR = 0.98 (0.23-4.17); P = 0.98, respectively].Conclusion The use of heart failure medication is high in TGA-AtrSO patients, although evidence of its benefit is limited. This study showed lower risk of mortality with use of RAAS inhibitors and beta-blockers in symptomatic patients only. These findings can direct future guidelines, supporting use of RAAS inhibitors and b-blockers in symptomatic, but not asymptomatic patients